Beta-irradiation apparatus

ABSTRACT

A beta-irradiation apparatus in which an irradiator is divided into at least two compartments which accommodate holders each of which is filled with a substance containing a beta-emitting radioisotope enclosed in a plurality of separate hermetic capsules arranged in a matrix. The holders in the compartments and the capsules in the holders are disposed so that by a suitable arrangement of the capsules, the desired intensity and geometry of the beta-radiation field is secured.

United States Patent [191 Mamin et al. Jan. 8, 1974 [54] BETA-(RADIATION APPARATUS 3,532,888 10/1970 Masefield et al. 250/84 X [76] Inventory Evgeny Borisovich Mamin 2,675,487 4/1954 Schallert et 250/[06 S UX 3,499,149 3 1970 c 11,1 l. 250 4 Tokmakov pereulok, 3-5, kv. 69; avanaug r /8 Viktor Alexeevich Makarov, KroPotkmskaya uhtsa 154; Primary ExaminerJames W. Lawrence Gahna Petmvna Komeeva prospekt Assistant Examiner-Davis L. Willis Bernadskogo, 111, kv. 148; Boris Attorney flolman & Stem Safronovich Poppel, ulitsa Nametkina, l l, kv. 21; Vyacheslav lvanovich Ivanov, Checersky pereulok, 4, korpus 2, kv. 29, all Of 57 ABSTRACT Moscow, USSR.

[22] Filed: Nov. 18, 1970 A beta-irradiation apparatus in which an irradiator is I divided into at least two compartments which accom- [211 Appl' 90523 modate holders each of which is filled with a substance containing a beta-emitting radioisotope en- [52] US. Cl. 250/106 S, 250/108 R closed in a plurality of separate hermetic capsules ar- [5l] Int. Cl. G2lh 5/00 ranged in a matrix. The holders in the compartments [58] Field of Search 250/84, 106 S, 106 SC, and the capsules in the holders are disposed so that by 250/106 R, 108 R a suitable arrangement of the capsules, the desired intensity and geometry of the betaradiation field is se- [56] References Cited cured.

UNITED STATES PATENTS 3,484,612 Kuenzli 250/106 R 5 Claims, 4 Drawing Figures PATENTEUJAR 8 1974 N GEES 4 BETA-IRRADIATION APPARATUS The present invention relates to beta-irradiation equip-ment intended to irradiate solid, liquid and gaseous physical and chemical specimens and also biological objects for the purpose of changing their physicochemical state, structural and biological properties.

There exist beta-irradiation units incoporating an irradiator which uses a substance containing a betaemitting radioisotope.

In these beta-irradiation units, the irradiator is an integral structure with a permanently built in substance containing a beta-emitting radioisotope and having no provision for varying the intensity and geometry of the beta-radiation field, which fact limits the potentialities of the cited units in view of the low penetrating ability of beta radiation. For the same reason, that is, because the irradiator is made integral with the substance containing a beta-emitting radioisotope, in charging and re-charging the beta-irradiation unit one has to deal with the total activity of the irradiator, the magnitude of which in certain cases is rather high. The latter fact makes it imperative in the case of charging such units to use expensive hot chambers" fitted with suitable remotely operated manipulators.

An object of the present invention is to provide a beta-irradiation apparatus having a readily dismountable irradiator.

Another object of the present invention is to provide a beta-irradiation apparatus permitting the transformation of the irradiator by varying its configuration and specific activity.

Still another object of the present invention is to provide a beta-irradiation apparatus providing for the charging and re-charging of the irradiator with a substance containing a beta-emitting radioisotope in a simple way.

With these and other objects in view, in a betairradiation apparatus using an irradiator which has a substance containing a beta-emitting radioisotope, the irradiator is, according to the invention, divided into a plurality of compartments adapted to accommodate holders arranged as a matrix, each of said holders being filled with a substance containing a beta-emitting radioisotope and enclosed in at least two hermetic capsules; the holders in the compartments and the capsules in the holders are disposed so that by a suitable arrangement of the matrix the desired intensity and configuration of the beta-radiation field is secured.

Owing to this structural arrangement of the betairradiation apparatus disclosed herein, the extent and specific activity of the irradiator can be varied between broad limits, and the possibility is provided for obtaining beta-radiation fields of pre-determined intensity and geometry. The dismountable and sectionalised construction of the irradiator simplifies the charging and re-charging of the irradiator.

The invention will be best understood from the following description of a preferred embodiment when read in connection with the accompanying drawings wherein:

FIG. 1 is a cut-away side elevation of a betairradiation apparatus according to the invention;

FIG. 2 is a cross-sectional view of the apparatus of FIG. 1;

FIG. 3 is a cut-away side elevation of a holder placed in the irradiator of the apparatus disclosed herein;

FIG. 4 is a cut-away view of a container for loading holders and the irradiator of a beta-irradiation apparatus according to the invention.

Referring to FIG. ll, there is a beta-irradiation appa ratus which comprises an irradiator 1 divided crosswise into at least six compartments intended to accommodate six holders 2 which are rigid extended structures of box-shaped section, filled with a substance containing a beta-emittin g radioisotope and enclosed in hermetic capsules 3. Each holder 2 accepts seven such capsules 3 which in this particular case are discshaped strontium beta-sources with an activity of 50 to 2,000 millicuries in terms of strontium-90, arranged in a predetermined order, so that any source can, if so desired, be replaced with a non-radioactive dummy. The holders 2 in the compartments and the capsules 3 in the holders 2 are disposed preferably in the form of a suitable matrix array so that the desired intensity and geometry of the beta-radiation field is secured. To facilitate transmission of B particle flux through the holder wall, apertures 2a are expediently provided therein.

To shield off the radiation and to prevent the capsules 3 from falling out of the holders 2 the latter are stoppered at the ends with plugs 4 and 5 (FIGS. 2 and), one of which, 5, can readily be removed.

From three sides (from the top and sides) the irradiation 1 is surrouned with a stationary radiation shield 6 (FIG. 2) whose material and thickness are determined by the maximum activity of the radioisotope used in the irradiator II. In this particular case, the shield 6 is made of lead blocks clad with stainless steel, the thickness of the blocks being mm. Qn oneside the shield 6 has openings through which the holders 2 are loaded into the irradiator I and which are closed by a common sliding door 7 and individual sliding doors 8 separate for each compartment of the irradiator l.

The radiation shielding of the irradiator I from the ends and from the bottom and also the feeding of speci' mens for irradiation is effected with the aid of a manually (or mechanically) driven trolley-mounted shield 9 (FIGS. 1 and 2)LLl-shaped in longitudinal cross-section. The trolley-mounted shield 9 is locked in the desired position and radiation leakage through the clearance between the stationary shield 6 and the trolleymounted shield 9 is prevented by cylindrical locators 10 (FIG. I).

The apparatus disclosed herein also comprises a container 11 (FIG. 4) for loading the capsules 3 into the holders 2 and the holders 2 into the irradiator 1.

The container III is a right-angled parallelepiped made from a material attenuating the radiation, has axially arranged openings for the holders 2, and is closed with readily dismountable upper and lower covers 12 at the ends.

The beta-irradiation apparatus disclosed herein can operate in two modes: irradiation of specimens and the charging and re-charging of the irradiator II.

In the former case, the sequence of operations should be as follows: the specimen to be irradiated (not shown in the drawing) is placed in one of the two spaces formed by the vertical members of the trolley-mounted shield 9 (FIG. 1) positioned outside the irradiator I in this case. Then the specimen is prepared for irradiation. The cylindrical locators 10 are withdrawn and the trolley-mounted shield 9 is placed in a position in which the specimen is under the irradiator 1, after which the cylindrical locators 10 are inserted into the respective recesses. While the specimen is being irradiated, another specimen is prepared for irradiation in the other space of the trolley-mounted shield.

The capsules 3 are loaded into a holder 2 as follows. The upper cover 12 is removed from the container 11, and the holder 2 with its plug 5 removed is inserted into the container. Using a mechanical (or air-operated) grip, the capsules 3 of the desired activity are introduced into the holder 2. After the holder 2 has been fully loaded, it is stoppered with the plug 5.

Thus, in loading a holder 2, the operator has only to deal with one capsule 3 at a time, because the capsules 3 are arranged in the holder 2 one above another and shield each other.

The container 11 carrying the holder 2 loaded with the capsules 3 is then moved towards the stationary shield 6 and, with the covers 12 removed, is positioned so that the dowels 13 (FIG. 4) fit into the holes 14 (FIGS. 1 and 2), after which the holder 2 is pushed into the compartment of the irradiator 1 corresponding to the predetermined distribution of activity. As this is done, the common sliding door 7 and the individual sliding door 8 must be open.

The remaining holders 2 are loaded with the capsules 3 and moved into the irradiator in exactly the same way. The holders 2 are withdrawn in reverse order.

The beta-irradiation apparatus disclosed herein, despite its relatively small overall dimensions, small weight and low cost (e.g., 800 X 500 X 500 mm, 600 kg, and 300 roubles without the radioisotope, respectively), produces fluxes of beta radiation of considerable intensity (the radiation rate in air is up to 50 rad/- sec) in a space measuring 250 X 250 X 150 mm, and enables the key radiation parameters to be varied between broad limits by re-grouping the holders and capsules. The apparatus disclosed herein can be used in a wide range of laboratory studies into the effects of ionizing radiations in chemistry, physics, biology and technology. With an irradiator of increased activity and extent, this type of apparatus can be used commercially, for example in irradiation chemistry and for the sterilization of medical products.

What we claim is:

l. A Beta-irradiation apparatus for producing and directing B-particles on an object to be irradiated, comprising: a stationary and immovable B-particle irradiator means for producing B-particle flux, said irradiator means including a plurality of independent holders arranged in a predetermined and fixed spatial configuration, each said holder containing a plurality of capsules containing a B -particle emitting isotope, said capsules of said plurality of holders being arranged substantially in a predetermined immovable array; a shielding housing means enclosing said irradiator means and defining a cavity for receiving the object to be treated; apertures provided in said holders for transmission of B particle flux from said isotope through the apertures, and door means for providing separate access to each of said plurality of independent holders, whereby the array may be changed by suitably assembling a static, immovable irradiator of capsules so as to obtain a B-radiation pattern of a required geometry and configuration.

2. The apparatus as claimed in claim 1, wherein said isotope is contained in a plurality of capsules arranged in elongated spaced and substantially parallel holders and in which said irradiator means includes a shielded container for loading said capsules into the holders and for loading said holders into the irradiator.

3. The apparatus as claimed in claim 2 in which said shielded container is provided with two readily dismountable end-covers.

4. The apparatus as claimed in claim 3 in which the ,B-ray emitting isotope comprises Strontium-90.

5. The apparatus as claimed in claim 2 in which selected ones of the capsules are nonradio isotopic so as to provide any required pattern and configuration of irradiation from said immovable irradiator. 

1. A Beta-irradiation apparatus for producing and directing Beta -particles on an object to be irradiated, comprising: a stationary and immovable Beta -particle irradiator means for producing Beta -particle flux, said irradiator means including a plurality of independent holders arranged in a predetermined and fixed spatial configuration, each said holder containing a plurality of capsules containing a Beta -particle emitting isotope, said capsules of said plurality of holders being arranged substantially in a predetermined immovable array; a shielding housing means enclosing said irradiator means and defining a cavity for receiving the object to be treated; apertures provided in said holders for transmission of Beta particle flux from said isotope through the apertures, and door means for providing separate access to each of said plurality of independent holders, whereby the array may be changed by suitably assembling a static, immovable irradiator of capsules so as to obtain a Beta -radiation pattern of a required geometry and configuration.
 2. The apparatus as claimed in claim 1, wherein said isotope is contained in a plurality of capsules arranged in elongated spaced and substantially parallel holders and in which said irradiator means includes a shielded container for loading said capsules into the holders and for loading said holders into the irradiator.
 3. The apparatus as claimed in claim 2 in which said shielded container is provided with two readily dismountable end-covers.
 4. The apparatus as claimed in claim 3 in which the Beta -ray emitting isotope comPrises Strontium-90.
 5. The apparatus as claimed in claim 2 in which selected ones of the capsules are non- radio isotopic so as to provide any required pattern and configuration of irradiation from said immovable irradiator. 